Multiply the amount of the discount by pairs of shoes:
21.75 x 7 = 152.25
Add that to the total she spent:
152.25 + 654.50 = 806.75
Divide the total by pairs of shoes:
806.75/7 = $115.25
The answer is C. $115.25
To determine the amount of water in the first 8 beakers, you will subtract the 19 ml that are in the 9th beaker from the total to see how much water was actually put into the first 8 beakers.
91 ml - 19 ml = 72 ml.
The 72 ml are divided evenly between 8 beakers.
72/8 = 9 ml
There would be 9 ml of water in each of the first 8 beakers.